1. Field of the Invention.
The present invention relates generally to the field of endotracheal tubes. More specifically, the present invention discloses an endotracheal tube having a beveled tip on its posterior wall and a radio-opaque stripe or other visual indicator to show proper orientation of the endotracheal tube as it is inserted into a patient""s airway.
2. Statement of the Problem.
Endotracheal tubes have been used for many years for ventilating patients. An endotracheal tube is typically a length of flexible tube with a connector at its proximal end for attachment to a ventilator, and an inflatable cuff adjacent to its distal end. The endotracheal tube is inserted through the patient""s mouth and advanced along the patient""s airway until the distal end of the endotracheal tube passes through the patient""s larynx. The cuff is then inflated through a small secondary lumen to occlude the airway surrounding the endotracheal tube, so that the patient""s ventilation is completely regulated and supplied by the ventilator.
Conventional endotracheal tubes are available in a variety of configurations. Some endotracheal tubes have a flexible plastic tube that can bend to accommodate a range of variations in patient anatomy. The opening between the patient""s vocal cords is a constriction in the airway that can be difficult for the healthcare provider to navigate with an endotracheal tube. The larynx is also a relatively delicate structure that can be easily bruised or torn. Ideally, the healthcare provider should be able to advance the distal end of the endotracheal tube through the opening between the patient""s vocal cords without causing trauma to the larynx or other portions of the patient""s airway.
In an effort to address these problems, some commercially available endotracheal tubes are equipped with a beveled distal tip. However, they are generally inserted at a random rotational orientation by healthcare providers. For example, in the case of a flexible endotracheal tube, many healthcare providers spin the endotracheal tube about its longitudinal axis while advancing it into the patient""s airway. These types of endotracheal tubes do not inherently have anterior or posterior sides. The spinning motion of the beveled tip tends to center the distal end of the endotracheal tube as it passes through the larynx and therefore may require less forward force to advance the endotracheal tube, but does little to prevent damage to the larynx caused by the rotating distal tip.
Other conventional endotracheal tubes are somewhat flexible, but have a preformed curvature that dictates a specific orientation for insertion of the endotracheal tube into the patient""s airway. These endotracheal tubes typically have a distal end that is beveled from the side, with a tip formed on the right side of the tube to minimize obstruction to the healthcare provider""s view of the larynx during insertion of the endotracheal tube (see, U.S. Pat. No. 5,873,362, col. 1, lines 20-34).
Some endotracheal tubes are also equipped with a radio-opaque stripe or a radio-opaque distal tip for monitoring the depth of insertion into the airway by means of x-ray or fluoroscopic imaging. However, these radio-opaque indicators are not normally used in monitoring the rotational orientation of the endotracheal tube.
Therefore, a need exists for an endotracheal tube having a distal tip that can be readily oriented by the healthcare provider to minimize the risk of trauma to the patient""s larynx. In particular, contrary to the conventional wisdom, placing the distal tip of the endotracheal tube on the posterior surface of the endotracheal tube helps to guide the endotracheal tube through the wider posterior opening between the patient""s vocal cords with a minimum resistance and trauma.
3. Prior Art.
The prior patents in the field includes the following:
Parker discloses an endotracheal tube having a beveled distal tip. The bevel extends toward, but not completely through the anterior wall of the tube, thus leaving a curved lip projecting from the anterior wall of the endotracheal tube. However, this anterior tip must pass through the narrower, anterior portion of the opening between the patient""s vocal cords, which may increase the risk of trauma. The rearward bevel and curved lip would also tend to accumulate mucus. If a fiber optic scope is used to insert the tube, the curved tip would at least partially block the view from within the lumen. If a fiber optic scope is used as a guide and the endotracheal tube is then advanced over the fiber optic scope, the curved tip at the distal end of the endotracheal tube would tend to move the endotracheal tube off-center relative to the fiber optic scope. Since healthcare providers are generally trained to the keep the fiber optic scope centered within the patients airway, this would tend to result in the endotracheal tube being advanced off-center through the opening in the vocal cords, which increases the risk of trauma to the vocal cords. In addition, if a suction catheter is advanced into the endotracheal tube, the rearward bevel at the distal end of the endotracheal tube would also tend to push the suction catheter into the mucosa lining the posterior surface of the airway, thereby further increasing the risk of trauma.
The patents to Nebergall et al. show a cannula with a radio-opaque tip. In particular, FIG. 1 of these patents shows an endotracheal tube with a beveled radio-opaque tip for monitoring the orientation of the tip in x-ray or fluoroscopic images.
Slingluff and Becker et al. disclose examples of several types of medical tubes or catheters with radio-opaque stripes.
Koerbacher discloses an endotracheal tube with a beveled distal end and a tip on the anterior wall of the tube. The distal tubular portion is connected by a flexible accordion section to the proximal tubular portion of the endotracheal tube.
4. Solution to the Problem
None of the prior art references discussed above show an endotracheal tube with a beveled distal tip on the posterior wall of the endotracheal tube, and a visual indicator (e.g., a radio-opaque stripe) on the wall of the endotracheal tube indicating the rotational orientation of the endotracheal tube. This configuration allows the healthcare provider to continually monitor the rotational position of the endotracheal tube so that its distal tip passes through the wider posterior portion of the opening in the patient""s larynx, thereby reducing the force necessary to advance the endotracheal tube and minimizing the risk of trauma to the patient""s larynx. The visual indicator on the proximal end of the endotracheal tube remains within the normal visual field of the healthcare provider throughout the procedure and can be continually monitored to maintain the proper rotational orientation for the endotracheal tube.
This invention provides a method and apparatus for intubating a patient""s airway using an endotracheal tube having a beveled distal end with a tip on the posterior wall of the endotracheal tube, and a visual indicator extending along the wall of the endotracheal tube. For example, the visual indicator can be a radio-opaque stripe extending the length of the anterior and/or posterior wall of the endotracheal tube. To use the apparatus with the patient in a supine position, the healthcare provider first takes a position above the patient head. The distal end of the endotracheal tube is then inserted into the patient""s mouth so that the visual indicator remains visible to the healthcare provider when viewed from above. The healthcare provider advances the endotracheal tube into the patient""s airway while monitoring the position of the visual indicator to ensure that the tip at the distal end of the endotracheal tube passes through the midline of wider posterior portion of the opening in the patient""s larynx.
These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description and the drawings.